SCM-36S molecular sieve, its preparation methods and applications, compositions, and methanol conversion methods.

Abstract

This invention relates to the field of molecular sieves, specifically to an SCM-36S molecular sieve, its preparation method, applications, compositions, and methanol conversion methods. This molecular sieve exhibits specific X-ray diffraction pattern characteristics. The SCM-36S molecular sieve with the X-ray diffraction pattern characteristics of this invention has thin crystal thickness, large external specific surface area, high acidity, high concentration of strong acids, and rapid molecular diffusion, resulting in high activity and stability. Using the molecular sieve of this invention in alkylbenzene cracking reactions or methanol conversion to olefins and / or aromatics yields high reactant conversion rates, product yields, and long service life.

Description

Technical Field

[0001] This invention relates to the field of molecular sieves, specifically to an SCM-36S molecular sieve, its preparation method and applications, compositions, and methanol conversion methods. Background Technology

[0002] In industry, molecular sieve materials are widely used in catalysis, ion exchange, adsorption, and separation due to their open structure and large surface area. Subtle differences in these material structures indicate variations in the various observable properties used to characterize them, such as their morphology, specific surface area, pore size, and the variability of these dimensions. This also implies significant differences in their catalytic and adsorption properties.

[0003] The basic framework structure of crystalline microporous zeolites is based on a rigid three-dimensional TO4 (SiO4, AlO4, etc.) unit structure; in this structure, TO4 shares oxygen atoms in a tetrahedral manner, and the charge balance of the framework tetrahedra such as AlO4 is achieved through surface cations such as Na. + H + The presence of these pores is maintained. This demonstrates that the framework properties of zeolites can be altered through cation exchange. Furthermore, zeolites possess a rich system of pores with specific pore sizes, which interweave to form a three-dimensional network structure. Even after the removal of water or organic matter from these pores, the framework remains stable (US 4439409). Based on this structure, zeolites not only exhibit good catalytic activity and excellent shape selectivity for various organic reactions, but also demonstrate good selectivity through modification (US 6162416, US 4954325, US 5362697).

[0004] The specific structure of a molecular sieve is determined by X-ray diffraction (XRD) patterns, which are measured using an X-ray powder diffractometer with a Cu-Kα ray source and a nickel filter. Different zeolite molecular sieves exhibit different XRD pattern characteristics. Existing molecular sieves, such as type A zeolites, type Y zeolites, and MCM-22 molecular sieves, all possess their own distinctive XRD patterns.

[0005] Furthermore, even if they share the same XRD pattern characteristics, different molecular sieves with different framework elements are still considered different. For example, TS-1 molecular sieve (US 4410501) and ZSM-5 molecular sieve (US 3702886) have the same XRD pattern characteristics but different framework elements. Specifically, TS-1 molecular sieve has a framework of Si and Ti and exhibits catalytic oxidation function, while ZSM-5 molecular sieve has a framework of Si and Al and exhibits acid catalytic function.

[0006] Furthermore, even with identical XRD patterns and the same type of framework elements, different molecular sieves can differ in their relative abundance of these elements. For example, zeolite X (US 2882244) and zeolite Y (US 3130007) share the same XRD pattern and both contain Si and Al as framework elements, but their relative abundances of Si and Al differ. Specifically, zeolite X has a Si / Al molar ratio below 1.5, while zeolite Y has a Si / Al molar ratio above 1.5. Summary of the Invention

[0007] The purpose of this invention is to provide an SCM-36S molecular sieve, its preparation method and applications, as well as a methanol conversion method. This SCM-36S molecular sieve has the advantages of thin crystal thickness, large external specific surface area, high acid content, high concentration of strong acids, fast molecular diffusion, simple preparation method, and high yield, making it a novel type of molecular sieve.

[0008] To achieve the above objectives, a first aspect of the present invention provides an SCM-36S molecular sieve having the X-ray diffraction pattern shown in the table below.

[0009]

[0010] Where a: ±0.30°, b: varies with 2θ.

[0011] A second aspect of the present invention provides a method for preparing the molecular sieve described herein, the method comprising: preparing a crystallization solution by mixing a silicon source, sodium aluminate, sodium hydroxide, an organic structure directing agent, and water; separating and drying the solution after crystallization treatment; wherein the sodium aluminate contains 38-43% Al2O3 by weight and 30-33% Na2O by weight; the organic structure directing agent contains a trimethylethylammonium ion structure; and the molar ratio of the silicon source (SiO2), sodium aluminate (Al2O3), sodium hydroxide, organic structure directing agent (trimethylethylammonium ion), and water in the crystallization solution is 1:0.016-0.050:0.10-0.20:0.15-0.30:10-50.

[0012] A third aspect of the present invention provides the application of the molecular sieve described herein in the preparation of adsorbents and / or catalysts.

[0013] A fourth aspect of the present invention provides a composition comprising the molecular sieve described herein.

[0014] The fifth aspect of this invention provides the application of the molecular sieve described herein in alkylbenzene cracking reactions or methanol conversion to olefins and / or aromatics.

[0015] A sixth aspect of the present invention provides a methanol conversion method, the method comprising: reacting methanol with a catalyst to obtain olefins and / or aromatics, wherein the catalyst comprises the molecular sieve described in the present invention.

[0016] Through the above technical solution, the present invention has the following advantages:

[0017] The SCM-36S molecular sieve with the X-ray diffraction pattern characteristics of this invention has thin crystal thickness, large external specific surface area, high acid content, many strong acids, and fast molecular diffusion, and has high activity and stability.

[0018] The molecular sieve of the present invention is prepared by the method of the present invention, which is simple and has a high yield.

[0019] The molecular sieve of the present invention is used in alkylbenzene cracking reactions or methanol conversion to olefins and / or aromatics, resulting in high reactant conversion rates, product yields, and service life. Attached Figure Description

[0020] Figure 1 The X-ray diffraction (XRD) pattern of the sample in Example 1;

[0021] Figure 2 The image shown is a scanning electron microscope (SEM) image of the sample in Example 1.

[0022] Figure 3 The image shown is a transmission electron microscope (TEM) image of the sample in Example 1.

[0023] Figure 4 The X-ray diffraction (XRD) pattern of the sample in Example 2;

[0024] Figure 5 The image shown is a scanning electron microscope (SEM) image of the sample in Example 2.

[0025] Figure 6 The X-ray diffraction (XRD) pattern of the sample in Example 3;

[0026] Figure 7 The image shown is a scanning electron microscope (SEM) image of the sample in Example 3.

[0027] Figure 8 The X-ray diffraction (XRD) pattern of the sample in Example 4;

[0028] Figure 9 The X-ray diffraction (XRD) pattern of the sample in Comparative Example 1 is shown.

[0029] Figure 10 The image shows the X-ray diffraction (XRD) pattern of the sample in Comparative Example 2. Detailed Implementation

[0030] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0031] This invention provides an SCM-36S molecular sieve, which has the X-ray diffraction pattern shown in the table below.

[0032]

[0033] Where a: ±0.30°, b: varies with 2θ.

[0034] The SCM-36S molecular sieve provided by this invention has the aforementioned characteristics, which gives the molecular sieve a unique crystal structure, thin crystal thickness, large external specific surface area, large acid content, many strong acids, fast molecular diffusion, and high activity.

[0035] According to a preferred embodiment of the present invention, the molecular sieve has the illustrative chemical composition "SiO2·1 / nAl2O3·1 / mR", where 20≤n≤60 and 0.04≤m≤0.15; preferably 25≤n≤50 and 0.05≤m≤0.14; wherein R is an organic structure directing agent.

[0036] According to a preferred embodiment of the present invention, the molecular sieve crystals have a plate-like morphology with a thickness not exceeding 12 nm and a length and width of 100-550 nm each; preferably, the molecular sieve crystals have a plate-like morphology with a thickness not exceeding 10 nm and a length and width of 120-450 nm each.

[0037] According to a preferred embodiment of the present invention, the molecular sieve has crystals with a thickness of no more than 6 nm accounting for at least 60% of the total number of crystals.

[0038] According to a preferred embodiment of the present invention, the molecular sieve is a sodium-type molecular sieve with a total specific surface area of ​​not less than 350 m². 2 / gram, preferably 350-600 meters 2 / gram.

[0039] According to a preferred embodiment of the present invention, the molecular sieve is a sodium-type molecular sieve with an external specific surface area of ​​not less than 180 m². 2 / gram, preferably 180-300 meters 2 / gram.

[0040] According to a preferred embodiment of the present invention, the molecular sieve is a sodium-type molecular sieve with a total pore volume of not less than 1.30 cm³. 3 / gram, preferably 1.30-2.0 cm 3 / gram.

[0041] According to a preferred embodiment of the present invention, the molecular sieve is a sodium-type molecular sieve with a micropore volume of not less than 0.08 cm³. 3 / gram, preferably 0.08-0.20 cm 3 / gram.

[0042] According to a preferred embodiment of the present invention, the molecular sieve is a sodium-type molecular sieve with a micropore size of 0.30-0.70 nanometers, preferably 0.35-0.65 nanometers.

[0043] In this invention, the sodium-type molecular sieve is obtained by subjecting the dried molecular sieve to a first calcination treatment.

[0044] In this invention, the sodium-type molecular sieve is converted into a hydrogen-type molecular sieve through ammonium exchange and a second calcination.

[0045] According to a preferred embodiment of the present invention, the molecular sieve is a hydrogen-type molecular sieve with a total acid content of not less than 600 μmol / g, preferably 600-1600 μmol / g.

[0046] According to a preferred embodiment of the present invention, the molecular sieve is a hydrogen-type molecular sieve with a strong acid content of not less than 200 μmol / g, preferably 200-600 μmol / g.

[0047] In this invention, there are no special requirements for the preparation method of the molecular sieve, as long as a molecular sieve with the aforementioned characteristics can be obtained. According to a preferred embodiment of this invention, a method for preparing the molecular sieve of this invention is provided, the method comprising: preparing a crystallization solution by mixing a silicon source, sodium aluminate, sodium hydroxide, an organic structure directing agent, and water; separating and drying the solution after crystallization treatment; wherein the content of Al2O3 in the sodium aluminate is 38-43% by weight, and the content of Na2O is 30-33% by weight; the organic structure directing agent contains a trimethylethylammonium ion structure; in the crystallization solution, the molar ratio of the silicon source (SiO2), sodium aluminate (Al2O3), sodium hydroxide, organic structure directing agent (trimethylethylammonium ion), and water is 1:0.016-0.050:0.10-0.20:0.15-0.30:10-50.

[0048] By employing the method of this invention, molecular sieves with the aforementioned characteristics of this invention can be directly synthesized using inexpensive and simple organic structure-directing agents containing trimethylethylammonium ions, with high synthesis yield. The synthesized SCM-36S molecular sieve has a large external specific surface area, high acidity, and a high concentration of strong acids.

[0049] In this invention, the range of silicon sources is relatively wide. According to a preferred embodiment of this invention, the silicon source is selected from at least one of silica sol, silica gel, and silica fume.

[0050] In this invention, organic structure directing agents having a trimethylethylammonium ion structure are applicable to this invention. According to a preferred embodiment of this invention, the organic structure directing agent is a quaternary ammonium salt and / or quaternary ammonium base containing a trimethylethylammonium ion structure, preferably selected from at least one of trimethylethylammonium hydroxide, trimethylethylammonium chloride, trimethylethylammonium bromide and trimethylethylammonium iodide, more preferably trimethylethylammonium hydroxide.

[0051] According to a preferred embodiment of the present invention, the molar ratio of silicon source (SiO2), sodium aluminate (Al2O3), sodium hydroxide, organic structure directing agent (trimethylethylammonium ion), and water in the crystallization solution is 1:0.019-0.045:0.12-0.18:0.16-0.30:12-45.

[0052] In this invention, the conditions for crystallization treatment can be conventionally selected in the art. According to a preferred embodiment of this invention, the conditions for crystallization treatment include: a temperature of 150-180°C, preferably 155-175°C.

[0053] The crystallization treatment conditions include: a time of 1.5-9.0 days and a crystallization period of 2.0-8.0 days.

[0054] In this invention, there are no special requirements for the crystallization method. According to a preferred embodiment of this invention, the crystallization method is dynamic crystallization by rotation and / or stirring, with a rotation speed of 10-60 rpm and / or a stirring speed of 30-300 rpm.

[0055] In this invention, the drying conditions can be conventionally selected in the art. According to a preferred embodiment of the invention, the drying conditions include a temperature of 40-250°C, preferably 60-50°C.

[0056] According to a preferred embodiment of the present invention, the drying conditions include a drying time of 8-30 hours, preferably 10-20 hours.

[0057] According to a preferred embodiment of the present invention, the method further includes: performing a first roasting treatment after drying.

[0058] In this invention, the conditions for the first roasting can be conventionally chosen in the art. According to a preferred embodiment of this invention, the conditions for the first roasting include: a roasting temperature of 300-800℃, preferably 400-650℃.

[0059] According to a preferred embodiment of the present invention, the conditions for the first roasting include: a time of 1-10 hours, preferably 3-6 hours.

[0060] According to a preferred embodiment of the present invention, the method further includes: ammonium exchange after a first roasting treatment.

[0061] In this invention, the conditions for ammonium exchange can be conventionally chosen in the art. According to a preferred embodiment of the invention, the conditions for ammonium exchange include: the ammonium salt is selected from at least one of ammonium chloride, ammonium nitrate, ammonium carbonate and ammonium sulfate.

[0062] According to a preferred embodiment of the present invention, the conditions for ammonium exchange include: the concentration of ammonium ions in the ammonium salt solution is 0.1-1 mol / L.

[0063] According to a preferred embodiment of the present invention, the conditions for ammonium exchange include a solid-liquid ratio of 1:5 to 1:20.

[0064] According to a preferred embodiment of the present invention, the conditions for ammonium exchange include a temperature of 30-80°C.

[0065] According to a preferred embodiment of the present invention, the conditions for the ammonium exchange include a time of 1-8 hours.

[0066] According to a preferred embodiment of the present invention, the method further includes: performing a second roasting after ammonium exchange.

[0067] In this invention, the conditions for the second calcination can be conventionally chosen in the art. According to a preferred embodiment of this invention, the conditions for the second calcination include: a calcination temperature of 300-800℃, preferably 400-700℃.

[0068] According to a preferred embodiment of the present invention, the time is 1-8 hours, preferably 2-6 hours.

[0069] This invention provides an application of the molecular sieve described above in the preparation of adsorbents and / or catalysts.

[0070] The present invention provides a composition comprising the molecular sieve described herein.

[0071] This invention provides an application of the molecular sieve described herein in alkylbenzene cracking reactions or methanol conversion to olefins and / or aromatics.

[0072] The present invention provides a methanol conversion method, the method comprising: reacting methanol with a catalyst to obtain olefins and / or aromatics, wherein the catalyst comprises the molecular sieve described in the present invention.

[0073] The molecular sieve of the present invention is used for methanol conversion to prepare olefins and / or aromatics, and has the characteristics of high activity and long life.

[0074] According to the present invention, the aforementioned molecular sieves can be used in any physical form, such as powder, granules, or molded forms (e.g., strips, clover shapes, etc.). These physical forms can be obtained in any manner conventionally known in the art, without particular limitation.

[0075] In the context of this specification, in the XRD data of molecular sieves, w, m, s, and vs represent diffraction peak intensities, with w being weak, m being moderate, s being strong, and vs being very strong, as is well known to those skilled in the art. Generally, w is less than 20; m is 20–40; s is 40–70; and vs is greater than 70.

[0076] In the context of this specification, the structure of the molecular sieve is determined by X-ray diffraction (XRD), which is measured using an X-ray powder diffractometer with a Cu-Kα ray source and a nickel filter. Before sample testing, the crystallinity of the molecular sieve sample is observed using a scanning electron microscope (SEM) to confirm that the sample contains only one type of crystal, i.e., the molecular sieve sample is a pure phase. XRD testing is then performed to ensure that there are no interfering peaks from other crystals in the diffraction pattern.

[0077] In the context of this specification, including in the following examples and comparative examples, the X-ray powder diffractometer used for the molecular sieves is a Panalytical X-PERPRO type X-ray powder diffractometer, used to analyze the phase composition of the samples, and a CuKα ray source. Nickel filter, 2θ scanning range 2~50°, operating voltage 40KV, current 40mA, scanning rate 10° / min.

[0078] In the context of this specification, including in the following examples and comparative examples, the scanning electron microscope (SEM) used for the molecular sieves is an S-4800II field emission scanning electron microscope. The molecular sieves were observed using this SEM at a magnification of 40,000x. A randomly selected field of view was used to calculate the average sum of the crystal sizes in that field of view, and this operation was repeated 10 times. The average sum of the 10 averages was taken as the crystal size.

[0079] In the context of this specification, including in the following examples and comparative examples, the method for measuring the crystal thickness of the molecular sieve is as follows: The molecular sieve is observed using a transmission electron microscope (FEI G2F30 transmission electron microscope, operating voltage 300kV) at a magnification of 100,000x. A random field of view is selected, and the average sum of the thicknesses of all plate-like crystals in that field of view is calculated. This operation is repeated a total of 10 times. The average sum of the 10 averages is taken as the crystal thickness. The thickness of all crystals in that field of view is measured, and the percentage of crystals with a thickness not exceeding 8 nm is counted. This operation is repeated 5 times. The average of the 5 measurements is taken as the percentage of crystals with a thickness not exceeding 8 nm.

[0080] In the context of this specification, including in the following examples and comparative examples, the micropore size, pore volume, specific surface area, and external specific surface area of ​​the molecular sieve were measured by the nitrogen physical adsorption-desorption method (BET method): the nitrogen physical adsorption-desorption isotherm of the molecular sieve was measured using a Micromeretic ASAP2020M physical adsorption instrument, and then calculated using the BET equation and t-plot equation. The experimental conditions for this molecular sieve were: measurement temperature -196℃, and before measurement, the molecular sieve was heat-treated at 550℃ in air for 6 hours, followed by pretreatment in vacuum at 350℃ for 4 hours.

[0081] In the context of this specification, including in the following examples and comparative examples, the molecular sieve was analyzed using an inductively coupled plasma atomic emission spectrometer (ICP) model Varian 725-ES, and the elemental content, in molar terms, was determined by dissolving the analytical sample in hydrofluoric acid.

[0082] In the context of this specification, including the following examples and comparative examples, the acid content of the molecular sieves was determined using an Altamira AMI-3300 instrument with NH3-TPD chemisorption-desorption curves. Before testing, the samples were activated at 550°C for 1 hour, ammonia was adsorbed at 100°C for 20 minutes, and then desorbed and detected at 100–600°C. By analyzing the Gaussian peak distribution, the acid content corresponding to desorption temperatures above 300°C was considered the acid content of strong acids.

[0083] In the context of this specification, including in the following examples and comparative examples, the yield of molecular sieves refers to the percentage of the mass of the calcined sample relative to the sum of the masses of SiO2 and Al2O3 contained in the raw material.

[0084] In the context of this specification, including in the following examples and comparative examples, the catalyst is applied to the methanol conversion reaction:

[0085] The methanol conversion reaction uses methanol as a raw material to convert it into hydrocarbons such as olefins and aromatics under the action of a catalyst.

[0086] Methanol conversion rate % = (molar amount of feed methanol - molar amount of product methanol - 2 × molar amount of product dimethyl ether) / (molar amount of feed methanol) × 100%;

[0087] Selectivity of C2-C4 olefins % = (2 × molar amount of C2 olefins in the product + 3 × molar amount of C3 olefins in the product + 4 × molar amount of C4 olefins in the product) / (molar amount of feed methanol - molar amount of methanol in the product - 2 × molar amount of dimethyl ether in the product) × 100%.

[0088] Selectivity of aromatics % = (6 × molar amount of benzene in the product + 7 × molar amount of toluene in the product + 8 × molar amount of xylene in the product) / (molar amount of methanol in the feed - molar amount of methanol in the product - 2 × molar amount of dimethyl ether in the product) × 100%.

[0089] The present invention will be described in detail below through embodiments.

[0090] Example 1

[0091] A mixture was prepared by stirring 14.35 g of deionized water, 0.604 g of sodium aluminate (containing 40.5 wt% Al₂O₃, 30.6 wt% Na₂O, with the balance being H₂O), 0.366 g of sodium hydroxide, 7.06 g of trimethylethyl ammonium hydroxide solution (containing 25.00 wt% trimethylethyl ammonium hydroxide) (organic structure directing agent R), and 12.60 g of silica sol (containing 40.0 wt% SiO₂) at room temperature for 4 hours. The final material ratio (molar ratio) was as follows:

[0092] SiO2 / Al2O3 = 35;

[0093] NaOH / SiO2 = 0.18;

[0094] Trimethylethylammonium hydroxide (R) / SiO2 = 0.20;

[0095] H2O / SiO2 = 18.

[0096] The mixture was placed in a stainless steel reactor and heated at 170°C and 20 rpm for 3 days to crystallize. After crystallization, the mixture was filtered, washed, and dried overnight in an oven at 100°C. The XRD pattern of the obtained product is shown below. Figure 1 As shown in Table 1, this is the SCM-36S molecular sieve. The SiO2 / Al2O3 molar ratio of the molecular sieve was determined to be 35.1 using inductively coupled plasma atomic emission spectrometry (ICP). The chemical composition of the sample's molar ratio is "1SiO2·0.028Al2O3·0.08R". The SEM image of the sample is shown below. Figure 2 As shown, the TEM electron microscope image is as follows. Figure 3 As shown, the crystals have a nanosheet morphology with a length of 300 nm, a width of 240 nm, and a thickness of 9 nm. The sheet-like crystals with a thickness of no more than 6 nm account for 65% of the total number of crystals.

[0097] Table 1

[0098]

[0099] After calcination in air at 550℃ for 6 hours, the yield of molecular sieves was 87 wt%, and the specific surface area of ​​the molecular sieves was 442 m². 2 / gram, with an external specific surface area of ​​226 m² measured by the BET method. 2 / g; Total pore volume 1.69 cm 3 / gram, micropore volume is 0.11 cm³ 3 / g, with a micropore size of 0.56nm. Sodium-form SCM-36S molecular sieve was subjected to ammonium ion exchange with 0.2mol / L NH4NO3 solution (mass ratio 1:20) at 65℃ for 2 hours, followed by centrifugation and washing. The ammonium ion exchange was repeated twice. The resulting sample was dried overnight at 100℃ and calcined in air at 550℃ for 4 hours to obtain hydrogen-form SCM-36S molecular sieve sample. NH3-TPD analysis showed that the total acid content of this molecular sieve was 1180μmol / g, and the strong acid content was 441μmol / g.

[0100] Example 2

[0101] 12.82 g of deionized water, 0.650 g of sodium aluminate (containing 40.5 wt% Al₂O₃, 30.6 wt% Na₂O, with the balance being H₂O), 0.177 g of sodium hydroxide, 5.47 g of trimethylethylammonium hydroxide solution (containing 25.00 wt% trimethylethylammonium hydroxide) (organic structure directing agent R), and 10.86 g of silica sol (containing 40.0 wt% SiO₂) were stirred at room temperature for 4 hours to obtain a mixture. The final material ratio (molar ratio) was:

[0102] SiO2 / Al2O3 = 28;

[0103] NaOH / SiO2 = 0.15;

[0104] Trimethylethylammonium hydroxide (R) / SiO2 = 0.18;

[0105] H2O / SiO2 = 18.

[0106] The mixture was placed in a stainless steel reactor and heated at 165°C and 20 rpm for 4 days to crystallize. After crystallization, the mixture was filtered, washed, and dried overnight in an oven at 100°C. The XRD pattern of the obtained product is shown below. Figure 4As shown in Table 2, this is the SCM-36S molecular sieve. The SiO2 / Al2O3 molar ratio of the molecular sieve was determined to be 27.7 using inductively coupled plasma atomic emission spectrometry (ICP). The chemical composition of the sample's molar ratio is "1SiO2·0.036Al2O3·0.07R". The SEM image of the sample is shown below. Figure 5 As shown, the TEM electron microscope image and Figure 3 Similarly, the crystals exhibit a nanosheet-like morphology, with a length of 320 nm, a width of 260 nm, and a thickness of 9 nm. The sheet-like crystals with a thickness of no more than 7 nm account for 65% of the total number of crystals counted.

[0107] Table 2

[0108]

[0109] After calcination in air at 550℃ for 6 hours, the yield of the molecular sieve was 88 wt%, and the specific surface area of ​​the molecular sieve was 489 m². 2 / gram, with an external specific surface area of ​​245 m² measured by the BET method. 2 / g; Total pore volume 1.96cm 3 / gram, micropore volume is 0.11 cm³ 3 / g, with a micropore size of 0.56nm. Sodium-form SCM-36S molecular sieve was subjected to ammonium ion exchange with 0.2mol / L NH4NO3 solution (mass ratio 1:20) at 65℃ for 2 hours, followed by centrifugation and washing. The ammonium ion exchange was repeated twice. The resulting sample was dried overnight at 100℃ and calcined in air at 550℃ for 4 hours to obtain hydrogen-form SCM-36S molecular sieve sample. NH3-TPD analysis showed that the total acid content of the molecular sieve was 1346μmol / g, and the strong acid content was 488μmol / g.

[0110] Example 3

[0111] A mixture was prepared by stirring 4.77 g of deionized water, 0.481 g of sodium aluminate (containing 40.5 wt% Al₂O₃, 30.6 wt% Na₂O, with the balance being H₂O), 0.085 g of sodium hydroxide, 6.03 g of trimethylethylammonium hydroxide solution (containing 25.00 wt% trimethylethylammonium hydroxide) (organic structure directing agent R), and 8.61 g of silica sol (containing 40.0 wt% SiO₂) at room temperature for 4 hours. The final material ratio (molar ratio) was as follows:

[0112] SiO2 / Al2O3 = 30;

[0113] NaOH / SiO2 = 0.12;

[0114] Trimethylethylammonium hydroxide (R) / SiO2 = 0.25;

[0115] H2O / SiO2 = 14.

[0116] The mixture was placed in a stainless steel reactor and heated at 160°C and 30 rpm for 6 days to crystallize. After crystallization, the mixture was filtered, washed, and dried overnight in an oven at 100°C. The XRD pattern of the obtained product is shown below. Figure 6 As shown in Table 3, this is the SCM-36S molecular sieve. The SiO2 / Al2O3 molar ratio of the molecular sieve was determined to be 29.8 using inductively coupled plasma atomic emission spectrometry (ICP). The chemical composition of the sample's molar ratio is "1SiO2·0.033Al2O3·0.11R". The SEM image of the sample is shown below. Figure 7 As shown, the TEM electron microscope image and Figure 3 Similarly, the crystals exhibit a nanosheet-like morphology with a length of 280 nm, a width of 240 nm, and a thickness of 10 nm. The sheet-like crystals with a thickness of no more than 7 nm account for 65% of the total number of crystals counted.

[0117] Table 3

[0118]

[0119] After calcination in air at 550℃ for 6 hours, the yield of molecular sieves was 90 wt%, and the specific surface area of ​​the molecular sieves was 505 m². 2 / gram, with an external specific surface area of ​​249 m² measured by the BET method. 2 / g; Total pore volume 1.71cm 3 / gram, micropore volume is 0.10 cm³ 3 / g, with a micropore size of 0.57nm. Sodium-type SCM-36S molecular sieve was subjected to ammonium ion exchange with 0.2mol / L NH4NO3 solution (mass ratio 1:20) at 65℃ for 2 hours, followed by centrifugation and washing. The ammonium ion exchange was repeated twice. The resulting sample was dried overnight at 100℃ and calcined in air at 550℃ for 4 hours to obtain hydrogen-type SCM-36S molecular sieve. NH3-TPD analysis showed that the total acid content of this molecular sieve was 1206μmol / g, and the strong acid content was 461μmol / g.

[0120] Example 4

[0121] The raw materials and preparation steps are the same as in Example 1, but the raw material ratios are adjusted. The final material ratio (molar ratio) is as follows:

[0122] SiO2 / Al2O3 = 40;

[0123] NaOH / SiO2 = 0.16;

[0124] Trimethylethylammonium hydroxide (R) / SiO2 = 0.30;

[0125] H2O / SiO2 = 22.

[0126] The mixture was placed in a stainless steel reactor and heated at 155°C and 10 rpm for 7 days to crystallize. After crystallization, the mixture was filtered, washed, and dried overnight in an oven at 100°C. The XRD pattern of the obtained product is shown below. Figure 8 As shown in Table 4, this is the SCM-36S molecular sieve. The SiO2 / Al2O3 molar ratio of the molecular sieve was determined to be 40.3 using inductively coupled plasma atomic emission spectrometry (ICP). The chemical composition of the sample's molar ratio is "1SiO2·0.025Al2O3·0.14R". The SEM image of the sample is shown below. Figure 2 Similarly, TEM electron micrographs and Figure 3 Similarly, the crystals exhibit a nanosheet-like morphology, with a length of 310 nm, a width of 230 nm, and a thickness of 11 nm. Furthermore, sheet-like crystals with a thickness of no more than 8 nm account for 70% of the total number of crystals counted.

[0127] Table 4

[0128]

[0129]

[0130] After calcination in air at 550℃ for 6 hours, the yield of molecular sieves was 85 wt%, and the specific surface area of ​​the molecular sieves was 428 m². 2 / gram, with an external specific surface area of ​​220 m² measured by the BET method. 2 / g; Total pore volume 1.72 cm³ 3 / gram, micropore volume is 0.11 cm³ 3 / g, with a micropore size of 0.55nm. Sodium-form SCM-36S molecular sieve was subjected to ammonium ion exchange with 0.2mol / L NH4NO3 solution (mass ratio 1:20) at 65℃ for 2 hours, followed by centrifugation and washing. The ammonium ion exchange was repeated twice. The resulting sample was dried overnight at 100℃ and calcined in air at 550℃ for 4 hours to obtain hydrogen-form SCM-36S molecular sieve. NH3-TPD analysis showed that the total acid content of this molecular sieve was 985μmol / g, and the strong acid content was 389μmol / g.

[0131] Example 5

[0132] The raw materials and preparation steps are the same as in Example 1, but the raw material ratios are adjusted. The final material ratio (molar ratio) is as follows:

[0133] SiO2 / Al2O3 = 45;

[0134] NaOH / SiO2 = 0.14;

[0135] Trimethylethylammonium hydroxide (R) / SiO2 = 0.24;

[0136] H2O / SiO2 = 25.

[0137] The mixture was placed in a stainless steel reactor and heated at 175°C and 20 rpm for 2.5 days to crystallize. After crystallization, the mixture was filtered, washed, and dried overnight in an oven at 100°C. The XRD pattern of the obtained product was similar to... Figure 1 Similarly, as shown in Table 5, this is the SCM-36S molecular sieve. Inductively coupled plasma atomic emission spectrometry (ICP) determined the SiO2 / Al2O3 molar ratio of the molecular sieve to be 44.4, and the chemical composition of the sample's molar ratio is "1SiO2·0.022Al2O3·0.10R". The SEM image of the sample is similar to... Figure 2 Similarly, TEM electron micrographs and Figure 3 Similarly, the crystals exhibit a nanosheet-like morphology, with a length of 320 nm, a width of 270 nm, and a thickness of 12 nm. The sheet-like crystals with a thickness of no more than 8 nm account for 65% of the total number of crystals counted.

[0138] Table 5

[0139]

[0140] After calcination in air at 550℃ for 6 hours, the yield of the molecular sieve was 91 wt%, and the specific surface area of ​​the molecular sieve was 452 m². 2 / gram, with an external specific surface area of ​​246 m² measured by the BET method. 2 / g; Total pore volume 1.86 cm 3 / gram, micropore volume is 0.10 cm³ 3 / g, with a micropore size of 0.58nm. Sodium-form SCM-36S molecular sieve was subjected to ammonium ion exchange with 0.2mol / L NH4NO3 solution (mass ratio 1:20) at 65℃ for 2 hours, followed by centrifugation and washing. The ammonium ion exchange was repeated twice. The resulting sample was dried overnight at 100℃ and calcined in air at 550℃ for 4 hours to obtain hydrogen-form SCM-36S molecular sieve. NH3-TPD analysis showed that the total acid content of this molecular sieve was 867μmol / g, and the strong acid content was 372μmol / g.

[0141] Example 6

[0142] The raw materials and preparation steps are the same as in Example 1. The organic structure directing agent is trimethylethylammonium bromide (R). The raw material ratio is adjusted, and the final material ratio (molar ratio) is as follows:

[0143] SiO2 / Al2O3 = 50;

[0144] NaOH / SiO2 = 0.12;

[0145] Trimethylethylammonium bromide (R) / SiO2 = 0.28;

[0146] H2O / SiO2 = 28.

[0147] The mixture was placed in a stainless steel reactor and heated at 170°C and 40 rpm for 3.5 days for crystallization. After crystallization, the mixture was filtered, washed, and dried overnight in an oven at 100°C. The XRD pattern of the obtained product was similar to... Figure 1 Similarly, as shown in Table 6, this is the SCM-36S molecular sieve. Inductively coupled plasma atomic emission spectrometry (ICP) determined the SiO2 / Al2O3 molar ratio of the molecular sieve to be 49.4, and the chemical composition of the sample's molar ratio is "1SiO2·0.020Al2O3·0.10R". The SEM image of the sample is shown below. Figure 2 Similarly, TEM electron micrographs and Figure 3 Similarly, the crystals exhibit a nanosheet-like morphology, with a length of 300 nm, a width of 230 nm, and a thickness of 10 nm. The sheet-like crystals with a thickness of no more than 7 nm account for 65% of the total number of crystals counted.

[0148] Table 6

[0149]

[0150] After calcination in air at 550℃ for 6 hours, the yield of the molecular sieve was 88 wt%, and the specific surface area of ​​the molecular sieve was 467 m². 2 / gram, with an external specific surface area of ​​214 m² measured by the BET method. 2 / g; Total pore volume 1.79 cm 3 / gram, micropore volume is 0.12 cm³ 3 / g, with a micropore size of 0.56nm. Sodium-form SCM-36S molecular sieve was subjected to ammonium ion exchange with 0.2mol / L NH4NO3 solution (mass ratio 1:20) at 65℃ for 2 hours, followed by centrifugation and washing. The ammonium ion exchange was repeated twice. The resulting sample was dried overnight at 100℃ and calcined in air at 550℃ for 4 hours to obtain hydrogen-form SCM-36S molecular sieve. NH3-TPD analysis showed that the total acid content of the molecular sieve was 775μmol / g, and the strong acid content was 276μmol / g.

[0151] Example 7

[0152] The raw materials and preparation steps are the same as in Example 1. The organic structure directing agent is trimethylethylammonium chloride (R). The raw material ratio is adjusted, and the final material ratio (molar ratio) is as follows:

[0153] SiO2 / Al2O3 = 25;

[0154] NaOH / SiO2 = 0.16;

[0155] Trimethylethylammonium chloride (R) / SiO2 = 0.22;

[0156] H2O / SiO2 = 36.

[0157] The mixture was placed in a stainless steel reactor and heated at 165°C and 20 rpm for 5 days to crystallize. After crystallization, the mixture was filtered, washed, and dried overnight in an oven at 100°C. The XRD pattern of the obtained product was similar to... Figure 1 Similarly, as shown in Table 7, this is the SCM-36S molecular sieve. Inductively coupled plasma atomic emission spectrometry (ICP) determined the SiO2 / Al2O3 molar ratio of the molecular sieve to be 24.7, and the chemical composition of the sample's molar ratio is "1SiO2·0.040Al2O3·0.07R". The SEM image of the sample is similar to... Figure 2 Similarly, TEM electron micrographs and Figure 3 Similarly, the crystals exhibit a nanosheet-like morphology with a length of 290 nm, a width of 190 nm, and a thickness of 10 nm. The sheet-like crystals with a thickness of no more than 6 nm account for 65% of the total number of crystals counted.

[0158] Table 7

[0159]

[0160] After calcination in air at 550℃ for 6 hours, the yield of molecular sieves was 85 wt%, and the specific surface area of ​​the molecular sieves was 422 m². 2 / gram, with an external specific surface area of ​​209 m² measured by the BET method. 2 / g; Total pore volume 1.58cm 3 / gram, micropore volume is 0.11 cm³ 3 / g, with a micropore size of 0.56nm. Sodium-form SCM-36S molecular sieve was subjected to ammonium ion exchange with 0.2mol / L NH4NO3 solution (mass ratio 1:20) at 65℃ for 2 hours, followed by centrifugation and washing. The ammonium ion exchange was repeated twice. The resulting sample was dried overnight at 100℃ and calcined in air at 550℃ for 4 hours to obtain hydrogen-form SCM-36S molecular sieve sample. NH3-TPD analysis showed that the total acid content of the molecular sieve was 1486μmol / g, and the strong acid content was 524μmol / g.

[0161] Example 8

[0162] The raw materials and preparation steps are the same as in Example 1, but the raw material ratios are adjusted. The final material ratio (molar ratio) is as follows:

[0163] SiO2 / Al2O3 = 21;

[0164] NaOH / SiO2 = 0.18;

[0165] Trimethylethylammonium hydroxide (R) / SiO2 = 0.20;

[0166] H2O / SiO2 = 18.

[0167] The mixture was placed in a stainless steel reactor and heated at 170°C and 20 rpm for 3 days to crystallize. After crystallization, the mixture was filtered, washed, and dried overnight in an oven at 100°C. The XRD pattern of the obtained product was similar to... Figure 1 Similar to Table 1, this is an SCM-36S molecular sieve. Inductively coupled plasma atomic emission spectrometry (ICP) determined the SiO2 / Al2O3 molar ratio of the molecular sieve to be 20.8, and the chemical composition of the sample's molar ratio is "1SiO2·0.048Al2O3·0.07R". The SEM image of the sample is similar to... Figure 2 Similarly, the crystals exhibit a nanosheet-like morphology, with a length of 530 nm, a width of 420 nm, and a thickness of 12 nm. The sheet-like crystals with a thickness of no more than 6 nm account for 60% of the total number of crystals counted.

[0168] After calcination in air at 550℃ for 6 hours, the yield of the molecular sieve was 81 wt%, and the specific surface area of ​​the molecular sieve was 409 m². 2 / gram, with an external specific surface area of ​​184 m² measured by the BET method. 2 / g; Total pore volume 0.92cm 3 / gram, micropore volume is 0.10 cm³ 3 / g, with a micropore size of 0.56nm. Sodium-form SCM-36S molecular sieve was subjected to ammonium ion exchange with 0.2mol / L NH4NO3 solution (mass ratio 1:20) at 65℃ for 2 hours, followed by centrifugation and washing. The ammonium ion exchange was repeated twice. The resulting sample was dried overnight at 100℃ and calcined in air at 550℃ for 4 hours to obtain hydrogen-form SCM-36S molecular sieve sample. NH3-TPD analysis showed that the total acid content of the molecular sieve was 1561μmol / g, and the strong acid content was 542μmol / g.

[0169] Examples 9-16

[0170] Take H-type SCM-36S molecular sieve powder samples from Examples 1-8 (corresponding to Examples 9-16, for example, the molecular sieve of Example 1 corresponds to the specific implementation of Example 9), crush them, and sieve 1.0 g of the 20-40 mesh particle size fraction. Place the sample into a fixed-bed reactor for methanol conversion reaction. The reaction conditions are: reaction temperature 440-480℃, reaction pressure atmospheric pressure, and methanol weight hourly space velocity 4-8 h⁻¹. -1The specific reaction conditions for each embodiment are shown in Table 8. The products, catalyst activity, and product selectivity were analyzed using a Shimadzu GC-2014 gas chromatograph, as shown in Table 8.

[0171] Table 8

[0172]

[0173] Comparative Example 1

[0174] The raw materials and preparation steps are the same as in Example 1, but the raw material ratios are adjusted. The final material ratio (molar ratio) is as follows:

[0175] SiO2 / Al2O3 = 100;

[0176] NaOH / SiO2 = 0.18;

[0177] Trimethylethylammonium hydroxide (R) / SiO2 = 0.20;

[0178] H2O / SiO2 = 18.

[0179] The mixture was placed in a stainless steel reactor and heated at 170°C and 20 rpm for 3 days to crystallize. After crystallization, the mixture was filtered, washed, and dried overnight in an oven at 100°C. The XRD pattern of the obtained product is shown below. Figure 9 As shown, the sample is uncrystallized and has an amorphous structure, and is not an SCM-36S molecular sieve.

[0180] Comparative Example 2

[0181] The raw materials and preparation steps are the same as in Example 1, but the raw material ratios are adjusted. The final material ratio (molar ratio) is as follows:

[0182] SiO2 / Al2O3 = 35;

[0183] NaOH / SiO2 = 0.40;

[0184] Trimethylethylammonium hydroxide (R) / SiO2 = 0.20;

[0185] H2O / SiO2 = 18.

[0186] The mixture was placed in a stainless steel reactor and heated at 170°C and 20 rpm for 3 days to crystallize. After crystallization, the mixture was filtered, washed, and dried overnight in an oven at 100°C. The XRD pattern of the obtained product is shown below. Figure 10 As shown, the sample is a molecular sieve with a mixture of MOR and FER structures, not an SCM-36S molecular sieve.

[0187] Comparative Example 3

[0188] The raw materials and preparation steps are the same as in Example 1, except that sodium aluminate is replaced with aluminum hydroxide. The raw material ratio is adjusted, and the final material ratio (molar ratio) is as follows:

[0189] SiO2 / Al2O3 = 35;

[0190] NaOH / SiO2 = 0.18;

[0191] Trimethylethylammonium hydroxide (R) / SiO2 = 0.20;

[0192] H2O / SiO2 = 18.

[0193] The mixture was placed in a stainless steel reactor and heated at 170°C and 20 rpm for 3 days to crystallize. After crystallization, the mixture was filtered, washed, and dried overnight in an oven at 100°C. The XRD pattern of the obtained product was compared with... Figure 9 Similarly, the sample was not crystallized and had an amorphous structure, and was not an SCM-36S molecular sieve.

[0194] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. An SCM-36S molecular sieve characterized by, The molecular sieve has an X-ray diffraction pattern shown in the following table, wherein, a: ±0.30°, b: varies with 2θ; The molecular sieve has a schematic chemical composition "SiO2•1 / nAl2O3•1 / mR", 20≤n≤60, 0.04≤m≤0.15, and R is an organic structure directing agent.

2. The molecular sieve according to claim 1, wherein, 25≤n≤50, 0.05≤m≤0.14; and / or The crystals of the molecular sieve have a platelet morphology with a thickness of no more than 12 nm, and a length and a width of each being 100-550 nm; and / or The crystals of the molecular sieve with a thickness of no more than 6 nm account for at least 60% of the total number of crystals.

3. The molecular sieve of claim 1, wherein, The crystals of the molecular sieve have a platelet morphology with a thickness of no more than 10 nm, and a length and a width of each being 120-450 nm.

4. The molecular sieve of claim 1, wherein, The molecular sieve is a sodium-type molecular sieve: total specific surface area not less than 350 m2 / g 2 / gram; and / or external specific surface area of not less than 180 m2 / g 2 / gram; and / or total pore volume not less than 1.30 cm3 / g 3 / gram; and / or microporous pore volume is not less than 0.08 cm3 / g 3 / gram; and / or The micropore size is 0.30-0.70 nm.

5. The molecular sieve of claim 1, wherein, The molecular sieve is a sodium-type molecular sieve: total specific surface area of 350-600 m2 / g 2 / gram; and / or external specific surface area of 180-300 m2 / g 2 / gram; and / or Total pore volume is 1.30-2.0 cm3 / g 3 / gram; and / or Micropore pore volume is 0.08-0.20 cm3 / g 3 / gram; and / or The micropore size is 0.35-0.65 nm.

6. The molecular sieve of any one of claims 1-5, wherein, The molecular sieve is a hydrogen-type molecular sieve: The total acid amount is no less than 600 μmol / g; and / or The strong acid amount is no less than 200 μmol / g.

7. The molecular sieve according to claim 6, wherein, The total acid amount is 600-1600 μmol / g; and / or The strong acid amount is 200-600 μmol / g.

8. A process for the preparation of the molecular sieve of any of claims 1 to 7, characterized in that, The method comprises: preparing a crystallization solution by mixing a silicon source, sodium aluminate, sodium hydroxide, an organic structure directing agent and water, and separating and drying after crystallization treatment; wherein, The content of Al2O3 in the sodium aluminate is 38-43% by weight, and the content of Na2O is 30-33% by weight; The organic structure directing agent contains a trimethyl ethyl ammonium ion structure; In the crystallization solution, the molar ratio of the silicon source (calculated as SiO2), sodium aluminate (calculated as Al2O3), sodium hydroxide, the organic structure directing agent (calculated as trimethyl ethyl ammonium ion) and water is 1:0.016-0.050:0.10-0.20:0.15-0.30:10-50.

9. The preparation method according to claim 8, wherein, The silicon source is selected from at least one of silica sol, silica gel and white carbon black; and / or The organic structure directing agent is a quaternary ammonium salt and / or a quaternary ammonium base containing a trimethyl ethyl ammonium ion structure.

10. The production method according to claim 8, wherein The organic structure directing agent is selected from at least one of trimethyl ethyl ammonium hydroxide, trimethyl ethyl ammonium chloride, trimethyl ethyl ammonium bromide and trimethyl ethyl ammonium iodide.

11. The method of making according to claim 8, wherein, The organic structure directing agent is trimethyl ethyl ammonium hydroxide.

12. The preparation method according to claim 8, wherein, In the crystallization solution, the molar ratio of the silicon source (calculated as SiO2), sodium aluminate (calculated as Al2O3), sodium hydroxide, the organic structure directing agent (calculated as trimethyl ethyl ammonium ion) and water is 1:0.019-0.045:0.12-0.18:0.16-0.30:12-45.

13. The preparation method according to claim 8, wherein, The conditions of the crystallization treatment include: a temperature of 150-180°C; and / or a time of 1.5-9.0 days; and / or The drying conditions include: temperature of 40-250℃, and / or time of 8-30h.

14. The preparation method according to claim 13, wherein, The crystallization conditions include: temperature of 155-175℃; and / or time of 2.0-8.0 days; and / or The drying conditions include: temperature of 60-50℃, and / or time of 10-20h.

15. The preparation method according to any one of claims 8-14, wherein, The method further comprises: performing a first calcination after drying; and / or The method further comprises: performing ammonium exchange after the first calcination; and / or The method further comprises: performing a second calcination after the ammonium exchange.

16. The preparation method according to claim 15, wherein, The first calcination conditions include: calcination temperature of 300-800℃; and / or time of 1-10h; and / or The ammonium exchange conditions include: ammonium salt is at least one selected from ammonium chloride, ammonium nitrate, ammonium carbonate and ammonium sulfate; and / or concentration of ammonium ion in the ammonium salt solution is 0.1-1mol / L; and / or solid-liquid ratio is 1:5-1:20; and / or temperature is 30-80℃; and / or time is 1-8h; and / or The second calcination conditions include: calcination temperature of 300-800℃; and / or time of 1-8h.

17. The preparation method according to claim 15, wherein, The first calcination conditions include: calcination temperature of 400-650℃; and / or time of 3-6h; and / or The second calcination conditions include: calcination temperature of 400-700℃; and / or time of 2-6h.

18. Use of the molecular sieve according to any one of claims 1-7 in the preparation of adsorbents and / or catalysts.

19. A composition characterized in that, The composition comprises the molecular sieve according to any one of claims 1-7.

20. Use of the molecular sieve according to any one of claims 1-7 in the cracking of alkylbenzenes or in the conversion of methanol to olefins and / or arenes.

21. A process for converting methanol, characterized in that, The method comprises: contacting methanol with a catalyst to obtain olefins and / or arenes, wherein the catalyst comprises the molecular sieve according to any one of claims 1-7.

22. The conversion method according to claim 21, wherein, The conditions of the contact reaction include: a reaction temperature of 450-480℃; and / or a reaction pressure of 0.05-0.5 MPa, a methanol weight hourly space velocity of 4-8 h -1 .

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